40 THE GLACIAL LAKE AGASSIZ. 



shore of Lake Agassiz, the elevation of the Great Northern Railway is 

 1,134 feet, or about 300 feet above the plain of the Red River Valley at 

 Grand Forks. Thence the surface in the next 17 miles westward rises to 

 1,525 feet, and this elevation is maintained somewhat uniformly, nowhere 

 exceeding 1,535 feet nor falling l)elow 1,450 feet, to the city of Devils 

 Lake, 1,464 feet above the sea, 60 miles west of Larimore. 



THE MANITOBA ESCARPMENT. 



A very remarkable series of highlands, forming the eastern limit of the 

 elevated plains of the northern part of North Dakota ^nd of Avestern 

 Manitoba and the Saskatchewan region, extends in a north-northwest 

 course 400 miles, from the Pembina Mountain to the Pasquia Hills. Along 

 much of this distance a steep, mountain-like escarpment, which was the 

 west shore of Lake Agassiz, rises 500 to 1,000 feet above the bed of that 

 lake, now the low plain bordering the Red River and the great lakes of 

 Manitoba. Topographically, this line of conspicuous highlands is allied 

 with the Coteau des Prairies by their together forming the western ascent 

 from the broad, continuous valley plain, which in its southeast part passes 

 from the Red River Valley to the lowland of the basin of the Minnesota 

 River. Both the Coteau des Prairies and the Manitoba escarpment consist, 

 beneath their drift covering, of nearly horizontal Cretaceous shales, whose 

 continuation has been removed by erosion on both sides of the Coteau, but 

 only east of the escarpment. 



Pembina ^fountain. — The southern end of the Pembina Mountain, 

 where it is reduced to rounded hills, about 100 feet above the lowland at 

 their east base and 1,300 feet above the sea, is in section 30, township 158 

 north, range 56 west, between the south and middle branches of Park 

 River. Thence for the next 5 miles northward this ascent is merely a slope 

 that rises 50 or 60 feet, or in some portions only 30 or 40 feet, within a 

 quarter or half mile from east to west, succeeded beyond by a moder- 

 ately rolling surface with slower ascent westward. Along the west line of 

 townships 159 and 160 of i-ange 56 tliis highland rises gradually in its 

 course from south to north, attaining an elevation about 1,500 feet above 

 the sea; and it holds this height quite uniformly northward to the Pembina 

 River, in the south ]iart of township 163, range 57, about 5 miles south of 



